Association of outcomes in point-of-care lung ultrasound for bronchiolitis in the pediatric emergency department

Background: Acute bronchiolitis (AB) is the most common lower respiratory tract infection in infants. Objective scoring tools and plain film radiography have limited application, thus diagnosis is clinical. The role of point-of-care lung ultrasound (LUS) is not well established. Objective: We sought to characterize LUS findings in infants presenting to the pediatric ED diagnosed with AB, and to identify associations between LUS and respiratory support (RS) at 12 and 24 h, maximum RS during hospitalization, disposition, and hospital length of stay (LOS). Methods: Infants ≤12 months presenting to the ED and diagnosed with AB were enrolled. LUS was performed at the bedside by a physician. Lungs were divided into 12 segments and scanned, then scored and summated (min. 0, max. 36) in real time accordingly: 0 - A lines with <3 B lines per lung segment. 1 - ≥3 B lines per lung segment, but not consolidated. 2 - consolidated B lines, but no subpleural consolidation. 3 - subpleural consolidation with any findings scoring 1 or 2. Chart review was performed for all patients after discharge. RS was categorized accordingly: RS (room air), low RS (wall O2 or heated high flow nasal cannula <1 L/kg), and high RS (heated high flow nasal cannula ≥1 L/kg or positive pressure). Results: 82 subjects were enrolled. Regarding disposition, the mean (SD) LUS scores were: discharged 1.18 (1.33); admitted to the floor 4.34 (3.62); and admitted to the ICU was 10.84 (6.54). For RS, the mean (SD) LUS scores at 12 h were: no RS 1.56 (1.93), low RS 4.34 (3.51), and high RS 11.94 (6.17). At 24 h: no RS 2.11 (2.35), low RS 4.91 (3.86), and high RS 12.64 (6.48). Maximum RS: no RS 1.22 (1.31), low RS 4.11 (3.61), and high RS 10.45 (6.16). Mean differences for all dispositions and RS time points were statistically significant (p < 0.05, CI >95%). The mean (SD) hospital LOS was 84.5 h (SD 62.9). The Pearson correlation coefficient (r) comparing LOS and LUS was 0.489 (p < 0.0001). Conclusion: Higher LUS scores for AB were associated with increased respiratory support, longer LOS, and more acute disposition. The use of bedside LUS in the ED may assist the clinician in the management and disposition of patient's diagnosed with AB.